Abstract: A prosthetic foot device includes an elongated continuous cantilever-spring, extending from an attachment section coupleable to a stump of an amputee to a toe section at a toe location of a natural foot. The cantilever-spring is elastically deformable under a load to store energy as the amputee steps onto the cantilever-spring and to release energy as the amputee steps off of the cantilever-spring. A cam is pivotally coupled to the cantilever-spring at a pivot. A resistance arm is coupleable to the stump of the amputee, and extends to a displaceable section engaging the cam. A lever arm is attached to the cantilever-spring and engages the cam. The cam operatively inter-couples the cantilever-spring and the resistance arm to elastically deform the resistance arm along with the cantilever-spring to collectively store more energy than the cantilever-spring alone.

Abstract: A prosthetic foot with an adjustable ankle includes an upper portion coupled to a socket of an amputee. A lower portion is adjustably coupled to the upper portion, and is attached to a foot member with heel and toe sections. A movable coupling is disposed between the upper and lower portions, and includes a displacement member slidably coupled to a displacement track. The movable coupling allows the toe section to pivot downward and the heel section to simultaneously displace forward.

Abstract: A prosthetic foot device includes an oblique attachment. The foot device can include an elongated forefoot portion having an upper attachment section disposed at an oblique angle and attached to an oblique surface of an attachment member coupled to a limb of an amputee. The forefoot portion can extend through ankle, arch and toe sections. The ankle section can include a discrete straight section that is vertically oriented and located at a rearmost of the foot device. The attachment section can extend to a position at the first third of a length of the foot device measured from the rearmost of the foot device. The foot device can be an energy storing and releasing member during use.

Abstract: A device prosthetic foot device with variable stiffness response includes a variable energy transfer medium disposed between first and second foot members to transfer at least some energy from the second member to the first member during use. The energy transfer medium includes a variable viscosity fluid such that the variable viscosity fluid, and thus the energy transfer medium, variably transfers energy between the first and second members to vary stiffness of the prosthetic foot device. The variable viscosity fluid can include a shear stiffening material that increases in viscosity as a load or strain, or rate of loading or rate of strain, applied, or a magneto or electro rheologic fluid responsive to a magnetic or electric field.

Abstract: A variable resistance cell and method provides a variable resistance response to a load factor, such as a load, a load rate, a strain, a strain rate, a pressure, or a deflection. A variable viscosity fluid is displacable between first and second chambers of an enclosure though an orifice in response to the load factor. The variable viscosity fluid has a viscosity that is variable corresponding to the load factor to vary an ability of the variable viscosity fluid to flow through the orifice. The variable viscosity fluid can be a shear stiffening material that increases in viscosity with an increase in a load factor applied to the shear stiffening material, a magneto rheologic fluid responsive to a magnetic field, or an electro rheologic fluid responsive to an electric field. The enclosure can be compressible between first and second positions.

Abstract: A prosthetic foot device includes an ankle section with a discrete, straight section in a substantially vertical orientation with a curved section on both sides. An attachment member can be coupled to a limb of an amputee. An elongated forefoot portion can have an upper attachment section attached to the attachment member, and can extend downwardly through the ankle section positioned at an ankle location of a natural foot, and forwardly through an arch section, to a toe section positioned at a toe location of a natural foot. The first curved section can interconnect the attachment section and the straight section, while the second curved section can interconnect the straight section and the arch section.

Abstract: A device for joining a prosthetic appendage to a prosthetic limb, comprising rotatable bearings encased within a cylindrical sleeve of resilient material, the cylindrical sleeve having its long axis colinear to the axis of rotation of the bearings. The bearings have a proximal portion affixed to the end of the limb, and a distal portion affixed to the appendage at the point where it is to be joined. The resilient sleeve comprises a top portion which is affixed to the outside surface of the proximal portion of the bearings, a bottom portion which is affixed to the outside surface of the distal portion of the bearings, and a typically bulging central portion which is not affixed to any part of the bearings. When the appendage is rotated relative to the limb about the axis of the bearings, such rotation is resiliently resisted by torsional flexure of the central portion of the resilient sleeve.

Abstract: A prosthetic foot, having a forefoot member and a heel member, is comprised of two separate members forming opposite halves of the foot generally about the longitudinal axis of the foot for simulating natural rotation of the toes of a real foot. The forefoot member of the foot forms a resilient arc extending from a fixture member to a toe position and has an attachment portion, a curvilinear spring portion, an arch portion, and a toe portion. The heel member extends between the forefoot member and a heel position and has an attachment portion and a heel portion. The heel member is preferably attached to the forefoot member by wrapping the members with a resin impregnated fibre. The foot preferably has a mating member such as a rib-and-groove type connection between the forefoot and heel members for preventing the forefoot and heel portions from sliding and rotating with respect to each other and thus prevents shear stress from being placed on the fibers holding the members together.

Abstract: A substantially nonbonded composite/metallic gun barrel is disclosed. The gun barrel has a metallic liner and a composite casing disposed thereabout. Unlike composite/metallic gun barrels of the prior art, the embodiments of the present invention provide little if any bonding between the composite casing and the metallic liner so as to decrease the warping of the gun barrel caused by the differing thermal expansion coefficients of the composite material and the metallic liner. In accordance with one aspect of the invention, a short binding layer is used to hold the composite casing to the metallic liner adjacent the chamber which holds a cartridge to be fired. The short layer prevents rotation of the casing and the liner with respect to one another, while preventing little risk of warping. In accordance with another aspect of the invention, a holding pin is inserted in the gun barrel to prevent the metallic liner and the composite casing from rotating relative one another.

Abstract: A substantially nonbonded composite/metallic gun barrel is disclosed. The gun barrel has a metallic liner and a composite casing disposed thereabout. Unlike composite/metallic gun barrels of the prior art, the embodiments of the present invention provide little if any bonding between the composite casing and the metallic liner so as to decrease the warping of the gun barrel caused by the differing thermal expansion coefficients of the composite material and the metallic liner. In accordance with one aspect of the invention, a short binding layer is used to hold the composite casing to the metallic liner adjacent the chamber which holds a cartridge to be fired. The short layer prevents rotation of the casing and the liner with respect to one another, while preventing little risk of warping. In accordance with another aspect of the invention, a holding pin is inserted in the gun barrel to prevent the metallic liner and the composite casing from rotating relative one another.

Abstract: A composite/metallic gun barrel is disclosed having a metallic liner and alternating first and second groups of fibers wrapped about the liner, the first groups being disposed in a first orientation generally perpendicular to the long axis of the liner, and the second groups including one or more layers disposed generally parallel with the long axis of the metallic liner. By controlling the amount of fibers in each group relative to the other group, the coefficients of thermal expansion in the radial direction can be regulated to provide a gun barrel having desired firing characteristics.